Liquid crystal display apparatus

ABSTRACT

A liquid crystal display apparatus includes: an array substrate; a seal material; and an opposite substrate, wherein the array substrate includes: a plurality of thin film transistors formed in correspondence to respective intersection parts of a plurality of gate wirings and a plurality of source wirings; a pixel electrode connected to the thin film transistor; an opposite electrode formed to face the pixel electrode; a gate extraction wiring that connects the gate wirings and a connection terminal formed in an outer area of the seal material; a conductive film that covers the gate extraction wiring with sandwiching a first insulation film therebetween; and a second insulation film that covers the conductive film in at least part of the outer area of the seal material, and wherein the conductive film is applied with an electrical potential of the opposite electrode.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Japanese Patent Application No.2011-070423 filed on Mar. 28, 2011, the entire subject matter of whichis incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates to a liquid crystal display apparatus. Morespecifically, this disclosure relates to improvements on visual qualityand reliability of a horizontal electric-field type liquid crystaldisplay apparatus.

BACKGROUND

In recent years, a new display apparatus having a thin and planardisplay panel using liquid crystals, electroluminescence, charged fineparticles and the like has been widely used instead of the conventionalcathode-ray tube. A liquid crystal display apparatus representative ofthe new display apparatus has not only thin and lightweight propertiesbut also low power consumption and low voltage driving characteristics.The liquid crystal display apparatus has the liquid crystals that aresealed between two substrates. One substrate is an array substratehaving a display area in which a plurality of pixels is arranged in amatrix shape, and the other substrate is an opposite substrate that isformed with a color filter, a black matrix (light shield film) and thelike. The array substrate and the opposite substrate are bonded with aseal material.

Specifically, since a thin film transistor (TFT) type liquid crystaldisplay apparatus has TFTs, which are switching elements, in respectivepixels on the array substrate, the respective pixels can have voltagesindependently driving the liquid crystals, and thus it is possible todisplay a high-quality image with less crosstalk. Also, each pixel isprovided with a gate wiring (scanning wiring) that controls on-offoperations of the TFT and a source wiring (signal wiring), whichintersecting with the gate wiring, to input image data. Typically, eachpixel corresponds to an area that is surrounded by the gate wirings andthe source wirings.

In an in-plane switching (IPS) type (horizontal electric-field type)liquid crystal display apparatus, a plurality of pixel electrodes andopposite electrodes (common electrodes) are arranged alternately at aninterval in a slit shape or pectinate shape, as viewed from a plan view,on the same layer or different layer on one array substrate. A generallyhorizontal electric-field is applied to a substrate surface, and thus animage is displayed. The IPS type has an improved viewing anglecharacteristic, compared to the conventional TN (Twisted Nematic) type.However, the IPS type has a lower light transmissivity, compared to theTN type, because the electrode parts of the pixel electrodes andopposite electrodes do not mostly contribute to the display.

It is known that an improved horizontal electric-field type apparatus,such as a fringe field switching (FFS) type (for example,JP-A-2009-265484 and JP-A-2010-049185. In a broader interpretation, itis described that the FFS type is also the IPS type). In the FFS typeliquid crystal display apparatus, the pixel electrodes and the oppositeelectrodes are formed on one array substrate, like the IPS type.However, the pixel electrodes and the opposite electrodes are arrangedwith being overlapped vertically with sandwiching an insulation filmtherebetween. Also, generally, the lower electrode has a plate (plane)shape and the upper electrode has a slit shape or pectinate shape havingan opening.

In the FFS type, the pixel electrode is any one of the lower electrodeand the upper electrode. In the FFS type, since the liquid crystals aredriven by the fringe electric-field between the upper and lowerelectrodes, the liquid crystals above the electrode parts of the upperelectrodes are also driven to contribute to the display. Thereby, thelight transmissivity is improved, compared to the IPS type.

SUMMARY

However, as described in JP-A-2009-265484 and JP-A-2010-049185, in thehorizontal electric-field type, a surface of the opposite substratefacing the liquid crystals is made of an insulation film such as blackmatrix, overcoat, color filter and the like, which are made of organicresin, and a transparent conductive film of the opposite electrode(common electrode), like the TN type, is not provided. Therefore, in thehorizontal electric-field type, the opposite substrate causes potentialvariation due to the electric-field generated from a gate extractionwiring on the array substrate, so that display non-uniformity occurs inthe vicinity of the display area adjacent to the gate extractionwirings.

In view of the above, JP-A-2009-265484 and JP-A-2010-049185 describethat a shield electrode (conductive film) for electric-field shield isarranged on the gate extraction wirings of the array substrate from adisplay area end to an area of the seal material, with sandwiching theinsulation film, thereby improving the display non-uniformity. However,the shield electrode on the gate extraction wirings is arranged in onlya part of the area of the seal material. Thus, it is not possible tosufficiently shield the electric-field, which is generated from the gateextraction wirings, in an area in which the shield electrode is notprovided, depending on layer configurations of the array substrate andthe opposite substrate, member characteristics and driving conditions.Thereby, the opposite substrate causes the potential variation, so thatthe display non-uniformity still occurs in the vicinity of the displayarea adjacent to the gate extraction wirings.

Also, when the shield electrode is made to extend to an outer area ofthe seal material, the shield electrode contacts moistures in theatmosphere in a configuration, in which the shield electrode is providedon the uppermost layer of the insulation film. As a result, the shieldelectrode may be corroded.

This disclosure provides at least a horizontal electric-field typeliquid crystal display apparatus having a configuration capable ofsuppressing display non-uniformity in the vicinity of a display areaadjacent to gate extraction wirings more efficiently, compared to therelated art, and capable of suppressing corrosion of a shield electrodeshielding a leakage electric-field generated from the gate extractionwirings.

In view of the above, a liquid crystal display apparatus comprises: anarray substrate that has a display area; a seal material that is formedto surround the display area; and an opposite substrate that is arrangedto face the array substrate with sandwiching liquid crystalstherebetween, the liquid crystals being sealed in an area surrounded bythe seal material, wherein the array substrate includes: a plurality ofthin film transistors that is formed in correspondence to respectiveintersection parts of a plurality of gate wirings and a plurality ofsource wirings arranged in the display area; a pixel electrode that isconnected to the thin film transistor; an opposite electrode that isformed to face the pixel electrode; a gate extraction wiring thatconnects the gate wirings and a connection terminal formed in an outerarea of the seal material; a conductive film that covers the gateextraction wiring with sandwiching a first insulation film therebetween;and a second insulation film that covers the conductive film in at leastpart of the outer area of the seal material, and wherein the conductivefilm is applied with an electrical potential of the opposite electrode.

According to this disclosure, a horizontal electric-field type liquidcrystal display apparatus may have a configuration capable ofsuppressing display non-uniformity in the vicinity of the display areaadjacent to the gate extraction wirings more efficiently, compared tothe related art and capable of suppressing corrosion of the shieldelectrode shielding a leakage electric-field generated from the gateextraction wirings.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and additional features and characteristics of thisdisclosure will become more apparent from the following detaileddescriptions considered with the reference to the accompanying drawings,wherein:

FIG. 1 is a schematic plan view illustrating a liquid crystal displayapparatus of a first illustrative embodiment;

FIG. 2 is an enlarged plan view illustrating an adjacent area S of aseal material of FIG. 1;

FIG. 3 is a sectional view taken along a line III-III of FIG. 2;

FIG. 4 is an enlarged plan view illustrating a pixel on an arraysubstrate of the liquid crystal display apparatus of the firstillustrative embodiment;

FIG. 5 is a sectional view taken along a line V-V of FIG. 4;

FIG. 6 is an enlarged plan view illustrating an adjacent area S of aseal material of a second illustrative embodiment;

FIG. 7 is a sectional view taken along a line VII-VII of FIG. 6;

FIG. 8 is an enlarged plan view illustrating an adjacent area S of aseal material of a third illustrative embodiment;

FIG. 9 is a sectional view taken along a line IX-IX of FIG. 8;

FIG. 10 is an enlarged plan view illustrating an adjacent area S of aseal material of a fourth illustrative embodiment;

FIG. 11 is a sectional view taken along a line XI-XI of FIG. 10;

FIG. 12 is an enlarged plan view illustrating an adjacent area S of aseal material of a fifth illustrative embodiment;

FIG. 13 is a sectional view taken along a line XIII-XIII of FIG. 12;

FIG. 14 is an enlarged plan view illustrating an adjacent area S of aseal material of a sixth illustrative embodiment; and

FIG. 15 is a sectional view taken along a line XV-XV of FIG. 14.

SUMMARY

Hereinafter, illustrative embodiments of a liquid crystal displayapparatus of this disclosure will be described with reference to thedrawings. In the meantime, the same reference numerals in the respectivedrawings for describing the illustrative embodiments indicate the sameor equivalent elements and the overlapped descriptions will beappropriately omitted.

First Illustrative Embodiment

First, a configuration of a liquid crystal display apparatus of thisdisclosure is briefly described. FIG. 1 is a schematic plan viewillustrating a liquid crystal display apparatus of a first illustrativeembodiment.

A liquid crystal display apparatus 100 has a plurality of pixels 30 thatis arranged in a matrix shape in a display area 50. Also, the liquidcrystal display apparatus has a liquid crystal display panel that isformed by bonding an array substrate 10, which has gate wirings 2,source wirings 5, TFTs and pixel electrodes (not shown) configuring thepixels 30 and common wirings 9 formed in the vicinity of an outer sideof the display area 50, and an opposite substrate 20, which is arrangedto face the array substrate 10 with sandwiching liquid crystalstherebetween, having a color filter, a black matrix 22 and the likeformed thereon. Although not shown, a deflection plate and a phase plateare bonded on respective surfaces of the liquid crystal panel and abacklight, an external circuit, a housing and the like are attached onthe surfaces, so that the liquid crystal display apparatus 100 iscompleted.

The array substrate 10 is divided into the display area 50 and a framearea 55 at the outer side of the display area 50 on an insulatingsubstrate 1 such as plastics. In the frame area 55, gate wiring drivingcircuits 70 and source wiring driving circuits 72 are mounted on aplurality of connection terminals (not shown) by a COG (Chip On Glass)mounting technology. Also, ends of the insulating substrate 1 areprovided with a plurality of connection terminals (not shown) forflexible substrates 74, 76, which are connected to external circuitsthat supply control signals, clocks, image data, driving voltages andthe like to the gate wiring driving circuits 70 and source wiringdriving circuits 72.

Meanwhile, although there are a plurality of gate extraction wirings 2 aor source extraction wirings 5 a, which extend from the gate wirings 2or source wirings 5 of the display area 50 to output parts of the gatewiring driving circuits 70 or source wiring driving circuits 72 withpassing the seal material 40, and a plurality of input wirings connectinput parts of the gate wiring driving circuits 70 or source wiringdriving circuits 72. Although, the plurality of connection terminals forflexible substrates 74, 76 provided at the end portions of theinsulating substrate 1, only parts thereof are shown in FIG. 1 so as tosimplify the drawing. Also, a conductive film 90 that will be describedlater is arranged above the gate extraction wirings 2 a.

In a small-sized panel, the total number of wirings is relatively small.Therefore, a driving circuit having integrated the gate wiring drivingcircuits 70, and the source wiring driving circuits 72 is used in manycases. Also, the flexible substrates 74, 76 are integrated into onepiece in many cases.

FIG. 2 is an enlarged plan view illustrating an adjacent area S of aseal material of the liquid crystal display apparatus shown in FIG. 1.FIG. 3 is a sectional view taken along a line III-III of FIG. 2.

Additionally, in FIG. 2, the black matrix 22, the overcoat 23 and thelike of the opposite substrate 20 are not shown so as to simplify thedrawing. Also, the pixels 30 of the display area 50 shown by the dottedline at the right side of FIG. 2 are arranged in a matrix shape. Adetailed configuration of the pixel 30 will be described later.

The gate extraction wiring 2 a is covered with a gate insulation film 3as a first insulation film. The common wiring 9 is formed at the samelayer as the source wiring 5 on the gate insulation film 3, and a commonpotential, which is an electrical potential of the opposite electrode,is applied to the common wiring 9. In the first illustrative embodiment,the common wiring 9 also becomes the conductive film 90 as the samelayer extending toward a connection terminal 16. The conductive film 90serves as a shield electrode that shields an electric-field generatedfrom the gate extraction wiring 2 a.

In an inner area of the seal material 40, the conductive film 90 ispreferably formed to cover the gate extraction wiring 2 a over thesubstantially entire part thereof from the end portion of the displayarea 50, in terms of shielding the electric-field generated from thegate extraction wiring 2 a. Also, the conductive film 90 ischaracterized in that it extends from the adjacency of the end portionof the display area 50 to an outer area of the seal material 40.

The seal material 40 has a seal function of bonding the array substrate10 and the opposite substrate 20 and enclosing liquid crystals 15therebetween. In general, the seal material 40 made of epoxy resin andthe like and is classified into heat-curing and photo-curing resins.Regarding the seal material 40, it is required for a material of theliquid crystals 15 that the impurities is not melt and leaked out.Usually, a permittivity ∈ of the seal material 40 is around 4.Therefore, if the conductive film 90 is formed including a part of theseal material 40, the area of the seal material 40 has an area, in whichthe conductive film 90 shielding the electric-field from the gateextraction wiring 2 a does not exist. Thereby, the electric-fieldgenerated from the gate extraction wiring 2 a still have an effect onthe opposite substrate 20.

However, in the first illustrative embodiment, the conductive film 90extends to the outer area of the seal material 40. Therefore, theconductive film 90 exists over the entire area of the seal material 40above the gate extraction wiring 2 a, so that it is possible to removemost of the influence of the electric-field generated from the gateextraction wiring 2 a on the opposite substrate 20.

The outer area of the seal material 40 between the array substrate 10and the opposite substrate 20 is usually atmospheric, and thus apermittivity ∈ of 1. Accordingly, the influence of the electric-fieldgenerated from the gate extraction wiring 2 a to the opposite substrate20 becomes small. However, as viewed from a plan view, it is preferablethat the conductive film 90 is formed to extend to the connectionterminal 16 with passing a position of an end portion 20 e of theopposite substrate of a side of the gate extraction wiring 2 a. Thereby,it is possible to suppress the influence of the electric-field generatedfrom the gate extraction wiring 2 a on the opposite substrate 20 stillmore efficiently.

In at least part of the outer area of the seal material 40, a protectivefilm 7 as a second insulation film covers the conductive film 90.Thereby, the conductive film 90 is covered with the protective film 7,so that it does not contact moistures in the atmosphere. Therefore, evenwhen the conductive film 90 is made of a metal film susceptible to thecorrosion, it is possible to suppress the corrosion.

Also, since the seal material 40 is bonded to the protective film 7 madeof an inorganic film such as oxide film and nitride film, an insulationfilm such as organic resin, or a stacked film thereof, it has higheradhesion to the array substrate 10, compared to the adhesion to atransparent oxide conductive film such as ITO (Indium Tin Oxide).

On the array substrate 10, on which the gate wiring driving circuits 70are mounted, the connection terminals 16 that are COG-connected tooutput terminals of the gate wiring driving circuits 70 are formed. Theconnection terminal 16 is connected to the gate extraction wiring 2 athrough a contact hole provided in the gate insulation film 3 andprotective film 7. The connection terminal 16 is formed at the samelayer as the upper electrode that is made of a transparent oxideconductive film such as ITO of the pixel 30 (which will be describedlater).

Also, as specifically described below, a connection part 86, which isformed at the same layer formed by extending the upper electrode of thepixel 30, and the common wiring 9 are connected to each other through acontact hole 13 provided in the protective film 7, and then the commonpotential is applied to the upper electrode.

The opposite substrate 20 is formed with the black matrix 22 made ofblack organic resin, the overcoat 23 made of a transparent organicresin, the color filters, alignment films (not shown) and the like on aninsulating substrate 21 made of glass, plastics and the like. Usually,each pixel 30 corresponds to one of the color filters based on threeprimary colors of red, blue and green.

Color filters based on four or more primary colors may be used so as toimprove color reproducibility.

In the general horizontal electric-field type liquid crystal displayapparatus 100, since a side of the opposite substrate 20 facing theliquid crystals 15 is not formed with an opposite electrode (commonelectrode) made of a transparent oxide conductive film such as ITO, theside facing the liquid crystal 15 is made of only an insulation filmbeing a dielectric. Accordingly, when the shield electrode that shieldsthe leakage electric-field generated from the gate extraction wiring 2 ais not provided, the insulating substrate 21, the black matrix 22, theovercoat 23, the color filters and the like of the opposite substrate 20cause the potential variation by the electric-field generated from thegate extraction wirings 2 a, so that the display non-uniformity occursin the vicinity of the display area 50 adjacent to the gate extractionwirings 2 a.

FIG. 4 is an enlarged plan view illustrating a pixel on the arraysubstrate of the liquid crystal display apparatus of the firstillustrative embodiment. FIG. 5 is a sectional view taken along a lineV-V of FIG. 4.

The pixel 30 of the first illustrative embodiment has an electrodeconfiguration, in which a lower electrode 6 is the pixel electrode andan upper electrode 8 is the opposite electrode in the FFS type liquidcrystal display apparatus 100.

The gate wiring 2, the gate extraction wiring 2 a and the like made ofmetal such as Al, Cr, Mo, Ti, Ta, W, Ni, Cu, Au and Ag or alloy orstacked film thereof are formed on the insulating substrate 1 of glass,plastics and the like.

Then, the upper layer thereof is covered with the gate insulation film 3made of an inorganic film such as oxide film, nitride film and the like.Also, a semiconductor film 4 and an ohmic contact film 41, which isformed by implanting impurities in the semiconductor film, are stackedand formed into an island shape on a part of the gate insulation film 3on the gate wiring 2.

Then, the source wiring 5, the source extraction wiring 5 a and the likemade of metal such as Al, Cr, Mo, Ti, Ta, W, Ni, Cu, Au and Ag or alloyor stacked film thereof are formed on the gate insulation film 3 so thatthey intersect with the gate wiring 2.

At this time, the common wiring 9 and the conductive film 90 made of thesame layer as the source wiring 5 are formed at the same time.

Also, a source electrode 51 and a drain electrode 52 formed at the samelayer as the source wiring 5 are formed to overlap with the ohmiccontact film 41. The ohmic contact film 41 exposed from the sourceelectrode 51 and drain electrode 52 is removed. The ohmic contact film41 between the source electrode 51 and drain electrode 52 is alsoremoved, and thus a channel part of a TFT is formed. The gate wiring 2below the channel part serves as a gate electrode, and a TFT as aswitching element is formed.

In the meantime, the semiconductor film 4 and the ohmic contact film 41may be formed not only in the TFT area but also along the source wiring,so that they are arranged below the source wiring 5. Also, thesemiconductor film 4 and the ohmic contact film 5 may be formed in anisland shape at an intersection part of the gate wiring 2 and the sourcewiring 5, so as to suppress the breaking of the source wiring 4.

The plate-shaped lower electrode 6 is a pixel electrode, and theelectrode is made of a transparent oxide conductive film such as ITO incase of a transmissive type. In a reflective type, the lower electrodeis made of metal such as Al, Ag and Pt or alloy or stacked film thereof,and a surface thereof may be made of a conductive film having highreflectivity. A part of the lower electrode 6 is formed on the drainelectrode 52 with stacked and is electrically connected thereto. In themeantime, a part of the lower electrode 6 may be formed at a lower layerof the drain electrode 52 and electrically connected thereto.

An upper layer of the source wiring 5, the TFT, the lower electrode 6and the like is covered with the protective film 7 that is made of aninorganic film such as oxide film and nitride film, an insulation filmof organic resin or a stacked film thereof.

The upper electrode 8 made of a transparent oxide conductive film suchas ITO is formed on the protective film 7. The upper electrode 8 has aslit shape (opening shape) having openings 82, a pectinate shape (oneside of the opening 82 is an open end) or a stripe shape. The upperelectrode 8 is the opposite electrode, and the common potential isapplied thereto. The upper electrode 8 generates a fringe electric-fieldbetween the lower electrode 6 and the upper electrode 8 through theprotective film 7 in areas of the openings 82, thereby driving theliquid crystals 15.

Also, in the first illustrative embodiment, the upper electrode 8 of theopposite electrode is connected to the upper electrodes 8 of theadjacent pixels 30 by connection parts 84 and 86, which formed at thesame layer as the upper electrode 8, in the source wiring 5(upper-lower) direction and gate wiring 2 (left-right) direction,respectively. The connection parts 84 and 86 cover the substantialentire area of the gate wiring 2 and source wiring 5 and are formed intoa grating (mesh) shape, so that they lower the resistance of the upperelectrode 8 and shield the electric-field from the gate wiring 2 andsource wiring 5 to the liquid crystals 15.

Also, an opening 81 is provided at the upper electrode 8 on the TFT orconnection parts 84 and 86. This is to suppress the common potential ofthe upper electrode 8 from influencing the TFT characteristics. However,the opening 81 is also a cause of the electric-field leakage from thegate wiring 2 to the liquid crystals 15. Therefore, it is preferable tominimize a size of the opening 81, or the opening 81 may not be providedon the TFT.

Also, the connection parts 84 and 86, which is formed at the same layeras the upper electrode 8 of the pixel 30 at the periphery of the displayarea 50, are made to extend continuously, and the connection parts 84and 86 are connected to the common wiring 9 through the contact hole 13provided in the protective film 7 in the inner area of the seal material40 from the end portion of the display area 50. The connection part 86that is arranged between the end portion of the display area 50 and thecommon wiring 9 has also the function of shielding the electric-fieldfrom the gate extraction wiring 2 a. Also, it is possible to suitablydesign a size, a shape, the number and a position of the contact hole13. For example, in FIG. 2, the contact holes are formed in areas ofboth sides on the common wiring 9 between the adjacent gate extractionwirings 2 a. Thereby, it is possible to apply the common potential tothe upper electrode 8 of the opposite electrode from the common wiring 9via the connection part 86.

Also, since the connection parts 84 and 86 in the display area 50 havethe effect of shielding the electric-field from the gate wirings 2 andthe source wirings 5 to the liquid crystals 15, they function as a lightshield film in a normally black mode of the horizontal electric-fieldtype. According to this configuration, it is possible to omit the blackmatrix 22 that is usually provided along the gate wirings 2 or sourcewirings 5 formed in the display area 50 of the opposite substrate 20.

In the meantime, the connection parts 84 and 86 in the display area 50may be formed in only one direction of the source wiring 5 (upper-lower)direction and the gate wiring 2 (left-right) direction and may beconnected to the upper electrode 8 of the adjacent pixel 30.

In the assembling process of the liquid crystal panel, the alignmentfilms (not shown) made of organic resins such as polyimide are appliedto the array substrate 10 and the opposite substrate 20, and then anorientation process is performed by using the rubbing or photo-alignmenttechnique so that molecules of the liquid crystals 15 are directed in apredetermined direction.

The array substrate 10 and the opposite substrate 20 are overlapped sothat the alignment films thereof face each other and have a gap of aboutseveral micro-meters therebetween by a spacer member (not shown) made oforganic resin and the like, and then they are bonded by the sealmaterial 40 formed to surround the display area 50. The liquid crystals15 are sealed in the inner gap of the seal material 40.

A polarization plate and a phase plate are bonded on both surfaces ofthe liquid crystal panel formed as described above, and the drivingcircuits 70 for scanning lines, the driving circuits 72 for signal linesand the flexible substrates 74, 76 are mounted. An external circuit forsupplying various electric signals to the liquid crystal panel and abacklight unit are attached on a backside of the liquid crystal panel(in the transmissive type) and accommodated in a housing, and thus theliquid crystal display apparatus 100 is completed.

As described above, in the first illustrative embodiment 1, theconductive film 90 is provided on the gate extraction wirings 2 a evenin at least part of the outer area of the seal material 40. Therefore,compared to the related art, it is possible to suppress the influence ofthe electric-field from the gate extraction wirings 2 a on the oppositesubstrate 20.

Since the conductive film 90 is covered with the protective film 7 in atleast part of the outer area of the seal material 40, the conductivefilm does not contact the moistures in the atmosphere, so that it ispossible to suppress the corrosion of the conductive film 90.

Second Illustrative Embodiment

FIG. 6 is an enlarged plan view illustrating an adjacent area S of aseal material of a second illustrative embodiment. FIG. 7 is a sectionalview taken along a line VII-VII of FIG. 6.

In FIG. 6, the black matrix 22, the overcoat 23 and the like of theopposite substrate 20 are not shown so as to simplify the drawing. Thepixels 30 of the display area 50 shown by the dotted line at the rightside of FIG. 6 are arranged in a matrix shape, and the detailedconfiguration of the pixel 30 is equivalent to that of the firstillustrative embodiment.

In the second illustrative embodiment, single-layered conductive film 96is provided similarly to the first illustrative embodiment. However, theconductive film 96 is formed at the same layer as the lower electrode 6of the pixel electrode of the pixel 30. Similarly to the configurationof the lower electrode 6 and the drain electrode 52, the conductive film96 is formed and stacked on the common wiring 9 and electricallyconnected thereto. In the meantime, a part of the conductive film 96 maybe formed at the lower layer of the common electrode 9 and electricallyconnected thereto.

In the transmissive type, the lower electrode 6 made of a transparentoxide conductive film such as ITO. Accordingly, the lower electrode hasthe corrosion resistance higher than the metal film made of the samelayer as the common wiring 9, so that it is possible to further suppressthe corrosion of the conductive film 96, compared to the firstillustrative embodiment.

Third Illustrative Embodiment

FIG. 8 is an enlarged plan view illustrating an adjacent area S of aseal material of a third illustrative embodiment. FIG. 9 is a sectionalview taken along a line IX-IX of FIG. 8.

In FIG. 8, the black matrix 22, the overcoat 23 and the like of theopposite substrate 20 are not shown so as to simplify the drawing. Thepixels 30 of the display area 50 shown by the dotted line at the rightside of FIG. 8 are arranged in a matrix shape, and the detailedconfiguration of the pixel 30 is equivalent to that of the firstillustrative embodiment.

In the first and second illustrative embodiments, single-layeredconductive film 90 is provided. However, in the third illustrativeembodiment, the conductive film made of a first conductive film 91 and asecond conductive film 92 that are formed at different layers. The firstconductive film 91 is formed in at least part of the outer area of theseal material 40 and is covered with the protective film 7 that is asecond insulating film. The second conductive film 92 is formed on theprotective film 7, as a second insulating film, in the inner area of theseal material 40 and is not formed in the outer area of the sealmaterial 40. Also, a junction part between the first conductive film 91and the second conductive film 92 has an overlapping part in the area ofthe seal material 40 or inner area of the seal material 40.

The first conductive film 91 is formed at the same layer as the sourcewiring 5 and the common wiring 9, and the second conductive film 92 isformed at the same layer as the upper electrode 8 of the oppositeelectrode formed on the protective film 7.

The junction part between the first conductive film 91 and the secondconductive film 92 has an overlapping part in the area of the sealmaterial 40 or inner area of the seal material 40, and the firstconductive film and the second conductive film are connected through acontact hole 11 provided in the protective film 7. By thisconfiguration, since the second conductive film 92 is formed on the gateextraction wiring 2 a in the inner area of the seal material 40, thefirst conductive film 91 may not be formed except for the adjacency areaof the seal material 40, in the inner area of the seal material 40.

Also, the second conductive film 92 is connected to the common wiring 9through a contact hole 12 provided in the protective film 7. Thereby,the common potential is applied to the first conductive film 91 and thesecond conductive film 92.

In FIG. 8, the contact holes 11, 12 provided in the protective film 7are formed in both sides of the common wiring 9 between the adjacentgate extraction wirings 2 a. However, the contact holes 11, 12 may beformed in any one of the both sides, as long as the electricalconnection can be made. Also, it is possible to suitably design thesizes, shapes and numbers of the contact holes 11, 12.

The junction part between the first conductive film 91 and the secondconductive film 92 has the overlapping part, and thus the conductivefilm on the gate extraction wiring 2 a is configured to not bedisconnected on the way, as viewed from a plan view. By thisconfiguration, it is possible to substantially shield the electric-fieldgenerated from the gate extraction wirings 2 a.

In the below, the operations and effects that are obtained as theconductive film is configured with the two layers are described. Thefirst conductive film 91 is formed in at least part of the outer area ofthe seal material 4 and thus securely shields the electric-fieldgenerated from the gate extraction wirings 2 a. The area of theconductive film that is formed in at least part of the outer area of theseal material 40 is covered with the protective film 7 so as to suppressthe corrosion due to the moistures in the atmosphere. Since the secondconductive film 92 is formed in the area or inner area of the sealmaterial 40, it does not contact the moistures in the atmosphere, sothat the corrosion is unlikely caused. Accordingly, the secondconductive film 92 is formed on the protective film 7, so that athickness of the insulation film between the gate extraction wiring 2 aand the second conductive film 92 is increased. Thereby, the secondconductive film 92 shields the electric-field generated from the gateextraction wirings 2 a and makes the load capacity of the gateextraction wirings 2 a to drive the gate wirings 2 smaller, compared tothe first and second illustrative embodiments.

Fourth Illustrative Embodiment

FIG. 10 is an enlarged plan view illustrating an adjacent area S of aseal material of a fourth illustrative embodiment. FIG. 11 is asectional view taken along a line XI-XI of FIG. 10.

In FIG. 10, the black matrix 22, the overcoat 23 and the like of theopposite substrate 20 are not shown so as to simplify the drawing. Thepixels 30 of the display area 50 shown by the dotted line at the rightside of FIG. 10 are arranged in a matrix shape, and the detailedconfiguration of the pixel 30 is equivalent to that of the firstillustrative embodiment.

The fourth illustrative embodiment has the conductive film having thetwo-layered configuration similarly to the third illustrativeembodiment. However, although the first conductive film 91 is formed atthe same layer as the source wiring 5 and the common wiring 9 in thethird illustrative embodiment, in the fourth illustrative embodiment,the first conductive film 91 is formed at the same layer as the lowerelectrode 6 of the pixel 30. At this time, the first conductive film 91is applied with the same common potential as that of the oppositeelectrode of the upper electrode 8, not the potential of the pixelelectrode of the lower electrode 6.

The second conductive film 92 is formed at the same layer as the upperelectrode 8 of the opposite electrode formed on the protective film 7.The second conductive film 92 is not formed in the outer area than theseal material 40. The second conductive film 92 is connected to thefirst conductive film 91 through the contact hole 11 in the area orinner area of the seal material 40, with partially overlapping with theseal material 40 or without overlapping with the seal material 40.

Also, the second conductive film 92 is connected to the connection part86 that is formed at the same layer formed by extending the upperelectrode 8 from the display area 50. Since the second conductive film92 is connected to the common wiring 9 through the contact hole 12, thecommon potential is applied to the upper electrode 8 through theconnection part 86.

The first conductive film 91 is the same layer as the lower electrode 6and made of a transparent oxide conductive film such as ITO, in thetransmissive type. Therefore, since the first conductive film has thecorrosion resistance higher than the metal film made of the same layeras the source wiring 5 and common wiring 9, it is possible to furthersuppress the corrosion, compared to the third illustrative embodiment.

Fifth Illustrative Embodiment

FIG. 12 is an enlarged plan view illustrating an adjacent area S of aseal material of a fifth illustrative embodiment. FIG. 13 is a sectionalview taken along a line XIII-XIII of FIG. 12.

In FIG. 12, the overcoat 23 and the like of the opposite substrate 20are not shown so as to simplify the drawing. However, an end portion 22e of the black matrix is shown to describe characteristics of the fifthillustrative embodiment. The pixels 30 of the display area 50 shown bythe dotted line at the right side of FIG. 12 are arranged in a matrixshape, and the detailed configuration of the pixel 30 is equivalent tothat of the first illustrative embodiment.

The fifth illustrative embodiment has the conductive film having thetwo-layered configuration similarly to the third illustrativeembodiment. However, the black matrix 22 of the opposite substrate 20 isnot formed over the entire area of the seal material 40, and the endportion 22 e of the black matrix is configured to partially overlap withthe seal material 40 or to not overlap with the seal material 40.

This is because the first conductive film 91 also functions as theshield film equivalent to the black matrix 22 in an area in which thefirst conductive film is configured by an opaque conductive film made ofthe same layer as the source wiring 5 and common wiring 9.

Since the black matrix 22 made of black organic resin is a member thatis easy to charge the electricity, it is one cause of the displaynon-uniformity that occurs in the vicinity of the display area 50, asthe opposite substrate 20 causes the potential variation. Therefore, theblack matrix 22 on the opposite substrate 20 facing the area made of theopaque conductive film is not formed, if possible, and an area thereofis reduced. Accordingly, the electric-field generated from the gateextraction wirings 2 a less causes the potential variation of theopposite substrate 20.

In the meantime, even when the conductive film 90 formed by the singlelayer, like the first illustrative embodiment, is the opaque metal filmmade of the same layer as the source wiring 5 and common wiring 9, thisdisclosure can be applied thereto. Also, the end portion 22 e of theblack matrix can be arranged up to the adjacency of the common wiring 9in the inner area of the seal material 40, so that it is possible tofurther reduce the area of the black matrix 22.

Sixth Illustrative Embodiment

FIG. 14 is an enlarged plan view illustrating an adjacent area S of aseal material of a sixth illustrative embodiment. FIG. 15 is a sectionalview taken along a line XV-XV of FIG. 14. The line XV-XV is in an areathat is not formed on the gate extraction wiring 2 a.

In FIG. 14, the black matrix 22, the overcoat 23 and the like of theopposite substrate 20 are not shown so as to simplify the drawing. Thepixels 30 of the display area 50 shown by the dotted line at the rightside of FIG. 14 are arranged in a matrix shape, and the detailedconfiguration of the pixel 30 is equivalent to that of the firstillustrative embodiment.

The sixth illustrative embodiment has the conductive film having thesingle-layered or two-layered configuration similarly to the first tofifth illustrative embodiments. However, openings 93 are formed in theconductive film of the areas that are formed not above the gateextraction wirings 2 a. Here, based on the third illustrativeembodiment, it is shown that the openings 93 are formed in the firstconductive film 91 in the outer area and inner area of the seal material40, which are formed not above the gate extraction wirings 2 a. Theopenings 93 may be formed in any one of the outer area and inner area ofthe seal material 40. Also, the openings 93 may be formed in the area ofthe seal material 40.

In the area of the opening 93, the protective film 7 is stacked on thegate insulation film 3 without sandwiching the conductive filmtherebetween. Accordingly, the adhesion with a base of the protectivefilm 7 is enhanced, compared to the protective film formed on theconductive film, so that the protective film 7 is not peeled off well,and thus the reliability may be further improved.

In the meantime, it is possible to suitably design the size, shape andnumber of the openings 93 as long as the conductive film maysufficiently shield the electric-field generated from the gateextraction wirings 2 a.

In the above illustrative embodiments, the pixel 30 has a configurationin which the lower electrode 6 is the pixel electrode and the upperelectrode 8 is the opposite electrode. However, this disclosure can bealso applied to a horizontal electric-field type liquid crystal displayapparatus having a configuration in which the lower electrode 6 is theopposite electrode and the upper electrode 8 is the pixel electrode. Inthis case, it is preferable that the second conductive film 92 made ofthe same layer as the upper electrode 8 is electrically separated fromthe upper electrode 8 of the pixel electrode in the vicinity of the endportion of the display area 50, and the common potential is applied tothe second conductive film 92.

Also, in the above illustrative embodiments, the FFS type has beenillustrated, in which the lower electrode 6 is the pixel electrode andthe upper electrode 8 is the opposite electrode. However, thisdisclosure can be also applied to an IPS type liquid crystal displayapparatus, in which the lower electrode 6 has a slit shape or pectinateshape.

Also, for an IPS type liquid crystal display apparatus in which thepixel electrode and the opposite electrode are formed at the sameuppermost layer, it is preferable that a pattern of the oppositeelectrode, to which the common potential is applied, is electricallyconnected to the conductive film, which is the shield electrode, in thevicinity of the end portion of the display area 50.

Also, in the above illustrative embodiments, the TFT has a channel etchinverted staggered type structure. However, this disclosure can be mayapplied to a horizontal electric-field type liquid crystal displayapparatus using a TFT of an etch stopper inverted staggered type, a topgate type and so on.

Also, in the above illustrative embodiments, it has been illustratedthat the driving circuit is COG-mounted. However, this disclosure can bealso applied to a horizontal electric-field type liquid crystal displayapparatus, in which a driving circuit is Tape Automated Bonding(TAB)-mounted or a driving circuit formed by TFTs is embedded on thearray substrate 10, as long as the gate extraction wirings 2 a areformed in the outer area of the seal material 40.

What is claimed is:
 1. A liquid crystal display apparatus comprising: an array substrate that has a display area; a seal material that is formed to surround the display area; and an opposite substrate that is arranged to face the array substrate with sandwiching liquid crystals therebetween, the liquid crystals being sealed in an area surrounded by the seal material, wherein the array substrate includes a plurality of thin film transistors that is formed in correspondence to respective intersection parts of a plurality of gate wirings and a plurality of source wirings arranged in the display area; a pixel electrode that is connected to the thin film transistor; an opposite electrode that is formed to face the pixel electrode; a gate extraction wiring that connects one of the plurality of gate wirings and a connection terminal formed in an outer area that is outside of the area surrounded by the seal material; a conductive film that covers the gate extraction wiring with sandwiching a first insulation film therebetween, in part of the outer area, the conductive film includes an opaque conductive film that functions as a light shielding film without light transmitting regions or openings, and the opaque conductive film extends from the outer area, below the seal material, and into the area surrounded by the seal material; and a second insulation film that covers the conductive film in at least part of the outer area, and wherein the conductive film is applied with an electrical potential of the opposite electrode, and the liquid crystal display apparatus is a horizontal electric-field type.
 2. The liquid crystal display apparatus according to claim 1, wherein the conductive film has a first conductive film and a second conductive film, wherein the first conductive film is formed below the second insulation film in at least part of the outer area, wherein the second conductive film is formed above the second insulation film in at least part of the area surrounded by the seal material and is not formed in the outer area, and wherein a junction part between the first conductive film and the second conductive film has an overlapping part.
 3. The liquid crystal display apparatus according to claim 2, wherein the first conductive film is formed at the same layer as the source wirings, and wherein the second conductive film is formed at the same layer as a layer above at least one of the pixel electrode and the opposite electrode.
 4. The liquid crystal display apparatus according to claim 2, wherein the first conductive film is formed at the same layer as a layer below at least one of the pixel electrode and the opposite electrode, and wherein the second conductive film is formed at the same layer as a layer above at least one of the pixel electrode and the opposite electrode.
 5. The liquid crystal display apparatus according to claim 2, wherein the first conductive film and the second conductive film are connected in at least one of an area of the seal material and the area surrounded by the seal material.
 6. The liquid crystal display apparatus according to claim 1, wherein the conductive film is formed to extend toward the connection terminal beyond a position of an end portion of the opposite substrate in the gate extraction wiring-side, in the outer area, as viewed from a plan view.
 7. The liquid crystal display apparatus according to claim 1, wherein a black matrix in the opposite substrate is not formed at an area that faces an area of the opaque conductive film.
 8. The liquid crystal display apparatus according to claim 1, wherein the conductive film is covered by the second insulation film in an area of the seal material above the gate extraction wirings.
 9. The liquid crystal display apparatus according to claim 1, wherein the conductive film is connected to the same layer as the opposite electrode in the vicinity of an end portion of the display area in the gate extraction wiring-side.
 10. The liquid crystal display apparatus according to claim 1, wherein the conductive film is formed to extend toward the connection terminal beyond a position of an end portion of a black matrix on an opposite substrate in the gate extraction wiring-side, in the outer area, as viewed from a plan view.
 11. The liquid crystal display apparatus according to claim 1, wherein a black matrix is made of organic resin.
 12. The liquid crystal display apparatus according to claim 1, wherein no electrode is provided on a liquid crystal side surface of the opposite substrate.
 13. The liquid crystal display apparatus according to claim 1, wherein a black matrix in the opposite substrate is not formed at an area that faces the opaque conductive film below the seal material. 